RC Voltage Control - Help?!

[NewHobbyMan]

I would like to create a lightweight (<5g) RC system that controls a reversible DC-voltage. This would require a on/off for the voltage (preferably achieving >12V) and a +/- polarity switch.

If anyone has an suggestions/designs/schematics etc. of how I could create this system please let me know! I would appreciate any advice, from individual components (receivers, transmitters, etc.) to circuit and connection diagrams. I have never custom built such a system -- please help!

Thanks,
the novice

[slipstick]

You are going to have a lot of trouble getting a transmitter, receiver and switch all weighing less than 5g total.

What range ? Are you intending to build the control system from scratch or buy it ? Do it need to be any particular type of control e.g. wired, radio, infra-red, ultrasonic ? If radio where do you live and what frequencies are available to you (legally) ?

As far as the switch goes, how much CURRENT must it switch. That's more important than voltage.

Steve

[NewHobbyMan]

Sorry for the confusion -- ultimately I want to remotely control a 12V battery voltage source (turn voltage on/off and switch polarity). The receiving end (receiver, switch, battery) would ideally weigh less than 10g, while the transmitter's weight is trivial. (I have 5g 12V batteries, so the receiver and switch/circuitry would be no more than 5g).

I had in mind to purchase the main components, e.g. a mini radio receiver and transmitter (I live in the USA). What I am not sure about it how to design the receiving-end of the system so to turn the battery on/off and switch the polarity. Furthermore, I am not clear on how to link the receiver to the control I want. Does this make sense?

In short, I am looking for a way to remotely control a 12V source while keeping the receiving-end's weight as light as possible.

[jeffs555]

You need to answer all of Steves questions before anyone can make any recommendation. CURRENT? Range?

Also, would help to know if cost is a consideration, and if you are capable of building electronics from scratch.

[NewHobbyMan]

It should switch a CURRENT of 10-50uA, and have a RANGE of at least 15ft (a range beyond this is not necessary).

I am capable of building electric circuits from scratch, and as far as cost goes, I'd like to keep it below $200, but this is flexible. This is budgeting a receiver/transmitter package in the range of $100.

[rmteo]

Plenty of options here:
http://www.linxtechnologies.com/Products/RF-Modules/

[jeffs555]

One easy and cheap option would be to hack one of micro RC cars. I don't think the receiver chip will handle 12 volts, but if you use a 5 volt regulator for the receiver chip, the motor driver transistors will probably switch the 12 volts ok. This page has some info on hacking. http://members.aol.com/rchelicam/microszr/microszr.htm
About halfway down, it shows the motor driver H-bridge. Where it shows the B+, you would have to separate this from the positive to the receiver chip and power the receiver from a regulator and the H-bridge directly from the 12 volts.

PS Here is a link to schematic for most of these receivers. http://tinyrc.com/forums/attachment.php?attachmentid=3519&d=1040748664

To convert to 12 volts, would need to remove D1, replace S8321 with a 3.3 volt regulator, and replace R14 and R15 with 1k resistors(or 10k for lower current). The transistors on that schematic are rated for 30 volts.